HOW: Started sel-ling land to oil companies for ser-vice stations in 1962. Bid on state land as freeways were built in Orange County. Went on to buy land for restaurants, stores. Found-ed Arnel & Affili-ates in 1968. Costa Mesa-based company owns, manages 5,200 apartments in OC, more than 2 million square feet of commercial space. Formed venture firm Westar Capital in 1987. Largest individual shareholder in DST Systems Inc., Kansas City-based financial software company. Has estimated worth of $1.5 billion.

RECENT: Philanthropy kick over past year. Along with wife, Julia, gave $8 million to new arts center at Chapman University, already a major contributor there. Family also gave $5 million for a pediatric emergency room at Children’s Hospital of Orange County, $2.5 million for Hoag Memorial Hospital Presbyterian, $2.5 million to Alzheimer’s Association.

PERSONAL: Former owner of Seattle Mariners. Former co-owner of AirCal with fellow OC 50 member William Lyon, sold business in 1981 to American Airlines. Second-generation Greek-American. First job was mowing lawns. 1993 winner of Horatio Alger Award; the Horatio Alger association’s treasurer, chairman emeritus. On numerous local, national boards. Active in politics. Served as U.S. ambassador to Spain from 2001 to 2004. Three children; daughter, Stephanie, last year opened Costa Mesa-based Arnel Estates, a luxury home real estate agency.

—Mark Mueller

DONALD BREN

Owner, chairman

Irvine Company, Newport Beach

Born in Los Angeles

Age: 80

Lives in Newport Beach

WHY: County’s leading landowner, landlord, with estimated 98 million square feet, including almost 500 office buildings, more than 40 retail centers, 122 apartment communities with nearly 47,000 units, three golf clubs and three resorts. Irvine Ranch among country’s most successful and most copied masterplanned communities. Wealthiest U.S. real estate developer, perhaps in the world, according to Forbes. Business Journal estimates wealth at $13 billion.

HOW: Founded homebuilder California Pacific Homes in 1958. In 1961 started Mission Viejo Co. with O’Neill-Moiso family and others; later sold stake to partners. Part of 1977 group that bought Irvine Co. Bought out most partners for $518 million in 1983. In 1991, paid $256 million court award to heiresses Joan Irvine Smith and mother Athalie Clarke for their shares. Became 100% shareholder in 1996.